title: Is dialysis modality a factor in the survival of patients initiating dialysis after kidney transplant failure?
abstract: BACKGROUND
  Kidney transplant failure (TF) is among the leading causes of dialysis initiation. Whether survival is similar for patients treated with peritoneal dialysis (PD) and with hemodialysis (HD) after TF is unclear and may inform decisions concerning dialysis modality selection.
  
  
  METHODS
  Between 1995 and 2007, 16 113 adult dialysis patients identified from the US Renal Data System initiated dialysis after TF. A multivariable Cox proportional hazards model was used to evaluate the impact of initial dialysis modality (1 865 PD, 14 248 HD) on early (1-year) and overall mortality in an intention-to-treat approach.
  
  
  RESULTS
  Compared with HD patients, PD patients were younger (46.1 years vs 49.4 years, p < 0.0001) with fewer comorbidities such as diabetes mellitus (23.1% vs 25.7%, p < 0.0001). After adjustment, survival among PD patients was greater within the first year after dialysis initiation [adjusted hazard ratio (AHR): 0.85; 95% confidence interval (CI): 0.74 to 0.97], but lower after 2 years (AHR: 1.15; 95% CI: 1.02 to 1.29). During the entire period of observation, survival in both groups was similar (AHR for PD compared with HD: 1.09; 95% CI: 1.0 to 1.20). In a sensitivity analysis restricted to a cohort of 1865 propensity-matched pairs of HD and PD patients, results were similar (AHR: 1.03; 95% CI: 0.93 to 1.14). Subgroups of patients with a body mass index exceeding 30 kg/m(2) [AHR: 1.26; 95% CI: 1.05 to 1.52) and with a baseline estimated glomerular filtration rate (eGFR) less than 5 mL/min/1.73 m(2) (AHR: 1.45; 95% CI: 1.05 to 1.98) experienced inferior overall survival when treated with PD.
  
  
  CONCLUSIONS
  Compared with HD, PD is associated with an early survival advantage, inferior late survival, and similar overall survival in patients initiating dialysis after TF. Those data suggest that increased initial use of PD among patients returning to dialysis after TF may be associated with improved outcomes, except among patients with a higher BMI and those who initiate dialysis at lower levels of eGFR. The reasons behind the inferior late survival seen in PD patients are unclear and require further study.
authors.affiliation: Division of Nephrology,1 St. Michael's Hospital and The Keenan Research Centre in the Li Ka Shing Knowledge Institute, Toronto, Ontario;
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Perl
authors.forename: James
authors.initials: J
authors.lastname: Dong
authors.forename: Caren
authors.initials: C
authors.lastname: Rose
authors.forename: Sarbjit Vanita
authors.initials: SV
authors.lastname: Jassal
authors.forename: John S
authors.initials: JS
authors.lastname: Gill
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D003131:Combined Modality Therapy; D005260:Female; D006801:Humans; D057194:Intention to Treat Analysis; D007676:Kidney Failure, Chronic / Q000401:mortality* / Q000628:therapy*; D016030:Kidney Transplantation; D008297:Male; D008875:Middle Aged; D010530:Peritoneal Dialysis / Q000401:mortality; D057216:Propensity Score; D016016:Proportional Hazards Models; D006435:Renal Dialysis / Q000401:mortality; D017211:Treatment Failure; D055815:Young Adult
keywords: Hemodialysis; US Renal Data System; kidney allograft loss; kidney transplantation; survival